Here's a tidbit from Wikipedia about the history of bisphosphonates:
Bisphosphonates were developed in the 19th century but were first investigated in the 1960s for use in disorders of bone metabolism. Their non-medical use was to soften water in irrigation systems used in orange groves. The initial rationale for their use in humans was their potential in preventing the dissolution of hydroxylapatite (also called hydroxyapatite), the principal bone mineral, thus arresting bone loss. Only in the 1990s was their actual mechanism of action demonstrated with the initial launch of Fosamax (alendronate) by Merck & Co.